It is well known in the field of heart valve repair to use implantable annuloplasty rings for surgical correction of certain mitral or tricuspid heart valve disorders. Clinical experience has shown that the repair of heart valves, where this technique is possible, produces significantly better long term results than do valve replacements.
Wright, U.S. Pat. No. 5,674,279, the contents of which are expressly incorporated by reference herein, describes in detail various effects of valvular dysfunction, known corrective procedures and various prosthesis that have been used in conjunction with mitral or tricuspid valve repair. Wright is also directed to an annuloplasty ring structure that has experienced considerable success in both mitral and tricuspid valve repair.
Known annuloplasty rings are either completely flexible or have an internal frame in at least a portion of the annuloplasty ring to impart some structural rigidity. Those annuloplasty rings with a rigid internal frame (i.e., a frame is rigid both along a circumferential axis of the frame and radially relative to the circumferential axis) can interfere with normal movement of the mitral valve annulus during diastole and systole. More particularly, during diastole the mitral valve annulus assumes a substantially planar configuration. During systole the anterior leaflet of the mitral valve bows into the left atrium due to aortic pressure, forming the mitral valve annulus into a partially flattened saddle shape. A rigid annuloplasty ring can interfere with the anterior segment of the mitral valve annulus assuming this bowed configuration during systole, leading to a condition known as systolic anterior motion or SAM. Thus, this is one limitation of the Carpentier-Edwards D-Shaped “Classic” semi-closed ring discussed in the Wright '279 patent, and the Carpentier-Edwards “Physio” ring.
Other rings are flexible, such as the Cosgrove-Edwards band, which is a fully flexible C-shaped ring and the Medtronic Duran ring, which is fully flexible and circular. Both of these rings are also discussed in the Wright '279 patent. Because flexible annuloplasty rings can be hard for surgeons to manipulate and implant due to their flexible nature, flexible rings and bands typically require a holder for implantation by a surgeon. Moreover, flexible rings are subject to axial compression or bunching when implantation sutures are tightened and tied during implantation.
The present invention is directed toward overcoming one or more of the problems discussed above.